Fergie needed to step away from The Black Eyed Peas to make an album about her own experiences.
The 42-year-old singer didn't think it was appropriate to pour her heart into a record about her own personal life with the 'Where is The Love?' group because she feels that would be a selfish thing to do.
She said: "I have lived so much and I needed somewhere to put all of my life experiences. I don't feel like it is fair to go on a Peas record and be like, 'Let me bust out my journals and make this all about me'.
"I don't know it's too selfish for me, so I just needed to let it all out."
The 'MILF$' singer is gearing up to release her much-awaited second studio album 'Double Dutchess' on September 22, and the busty blonde beauty can't wait to share her "soul" record with her fans.
However, she said she's not done with the group - comprised of will.i.am, Taboo and apl.de.ap - and hopes to make more music with them in the future.
She told SiriusXM: "I've always just been the little sis and part of groups and like that and I got to have a moment with 'The Dutchess' and such and amazing four albums with The Peas and hopefully more.
"I've always been a kind of misfit that didn't really fit in any particular character perfectly, so it's just a mishmash, but when you put it all together it really makes sense if you know.
"So I've got to have a soul album and do whatever I feel is organic and not try to fit in some mould."
Fergie teamed up with Nicki Minaj and Rick Ross on two tracks on the new record, 'You Already Know' and 'Hungry' respectively.
The song with superstar rapper Nicki was produced by Fergie's Black Eyed Peas bandmate will.i.am.